Dripless fuel dispenser nozzle

ABSTRACT

A fuel dispenser nozzle has a spout assembly for delivery of fuel into a vehicle fill pipe constructed to limit post-fueling dripping to an average of less than about three drops of fuel per fueling event.

TECHNICAL FIELD

This document relates to fuel dispensing nozzle systems, and more particularly to dripless nozzles for such systems.

BACKGROUND

Fuel dispensing nozzles in use at self service stations can create difficulties for customers by dripping automotive fuel, e.g., gasoline, on shoes and other articles of clothing as the nozzle is moved back and forth between the dispenser holster and the vehicle fill pipe. For example, dripping can occur while the customer handling the nozzle prior to fueling is attempting to insert the spout into the vehicle fill pipe or after refueling when the customer removes the spout from the fill pipe and returns the nozzle to its holstered position. Any fuel that does not drain into the vehicle fill pipe during refueling may drip onto the vehicle, the customer, or the ground. However, the nozzle spout retains any remaining fuel when the spout tip is raised above horizontal, including when the nozzle is holstered.

Fuel dripping from a dispensing nozzle is also an environmental concern, since any fuel escaping from the nozzle after removal from the vehicle fill pipe immediately evaporates into the atmosphere. Even fuel remaining in the spout when the nozzle is holstered will slowly evaporate into the atmosphere via the open end of the spout tip. The California Air Resources Board (CARB) has addressed these motor vehicle refueling problems by requiring that gasoline-dispensing nozzles demonstrate an ability to limit post-fueling dripping to an average of three (3) drops per fueling event. The CARB test procedure is described in the Phase II regulations under TP-201.2D “Post-Fueling Drips from Nozzle,” the complete disclosure of which is incorporated herein by reference.

SUMMARY

According to one aspect, a fuel dispensing nozzle comprises a nozzle body, a nozzle spout having a nozzle tip extending distally from the nozzle body, the nozzle spout defining a conduit for flow of fuel from the nozzle spout tip into a vehicle fuel tank fill pipe, and a dam disposed within the nozzle in communication with the conduit and defining a reservoir region for restricting draining of liquid fuel towards the nozzle spout tip. With the nozzle spout tip engaged in the vehicle fuel tank fill pipe and the nozzle spout disposed at a first angular orientation below horizontal, the dam defines a first volume of the reservoir region for retaining fuel against draining past the dam to drip from the nozzle spout tip. With the nozzle spout tip disengaged from the vehicle fuel tank fill pipe and the nozzle spout disposed at a second angular orientation below horizontal greater than the first angular orientation below horizontal, the dam defines a second volume greater than the first volume of the reservoir region for retaining fuel against draining past the dam to drip from the nozzle spout tip.

Preferred embodiments of this aspect may include one or more of the following additional features. The dam is disposed within the nozzle spout. The first angular orientation below horizontal is about 30° below horizontal. The first volume of the reservoir region for retaining fuel is about 20 drops. The second angular orientation below horizontal is up to about 90° below horizontal. The second volume of the reservoir region for retaining fuel is up to about 40 drops. The dam comprises a cylindrical wall member disposed coaxially within the nozzle spout. Preferably, the cylindrical wall member comprises a cylindrical tubular insert disposed in engagement with the wall of the conduit. A segment of the annular volume is occupied including in at least a lower region when dispensing fuel. The annular volume is occupied over an arcuate segment including at least a lower region when dispensing fuel. Preferably, the arcuate segment extends more than 180° including at least through the lower region. The annular volume is occupied by an insert member.

According to another aspect, a fuel dispenser nozzle comprises a nozzle body for delivering liquid fuel from a fuel dispenser towards a vehicle fuel tank, and a nozzle spout associated with the nozzle body for delivering liquid fuel from the nozzle body into a vehicle fuel tank fill pipe inclined at approximately 30° down from horizontal. The nozzle spout has an inner wall surface defining a liquid flow passageway from the nozzle body to a spout tip, the wall surface having a first region extending to the spout tip and being disposed with generally uniform radius about an axis, and a second region upstream from the first region and relatively closer to the nozzle body and being flared in a upstream direction, the second region of the inner wall surface being disposed at a predetermined angle to the axis. With the spout tip engaged in the vehicle fill pipe and the axis of the first portion disposed in general alignment with a vehicle fill pipe axis, the inner wall surface in the first region and the second region is disposed at effective angles below horizontal to encourage flow of liquid fuel toward the spout tip. When the spout tip is removed from the vehicle fill pipe after a predetermined interval following cessation of flow of fuel from the nozzle body into the conduit of the nozzle spout, dripping of residual liquid fuel from the spout tip is limited to a predetermined average number of drops of liquid fuel per fueling event.

Preferred embodiments of this aspect may include one or more of the following additional features. The predetermined interval of time is approximately 10 seconds. The predetermined average number of drops of liquid fuel dripped per fueling event is about 3 drops or less.

According to another aspect, a fuel dispenser nozzle comprises a nozzle body for delivering liquid fuel from a fuel dispenser towards a vehicle fuel tank, and a nozzle spout associated with the nozzle body for delivering liquid fuel from the nozzle body into a vehicle fuel tank fill pipe inclined at approximately 30° down from horizontal. The nozzle spout has an inner wall surface defining a liquid flow passageway from the nozzle body to a spout tip, the wall surface having a first region extending to the spout tip and being disposed with generally uniform radius about an axis, a second region upstream from the first region and relatively closer to the nozzle body and flared in a upstream direction, the second region of the inner wall surface being disposed at a first predetermined angle to the axis, and a third region upstream of the second region and relatively closer to the nozzle body and flared in an upstream direction, the third region of the inner wall surface being disposed at a second predetermined angle to the axis. With the spout tip engaged in the vehicle fill pipe and the axis disposed in general alignment with a vehicle fill pipe axis, the inner wall surface in the first, second, and third regions is disposed at effective angles below horizontal to encourage flow of liquid fuel toward the spout tip, whereby, when the spout tip is removed from the vehicle fill pipe after a predetermined interval following cessation of flow of fuel from the nozzle body into the liquid flow passageway of the nozzle spout, dripping of residual liquid fuel from the spout tip is limited to a predetermined average number of drops of liquid fuel per fueling event.

Preferred embodiments of this aspect may include one or more of the following additional features. The predetermined interval of time is approximately 10 seconds. The predetermined average number of drops of liquid fuel dripped per fueling event is about 3 drops or less. The first predetermined angle is about 22° to the axis. The second predetermined angle is about 7° to the axis.

According to yet another aspect, a fuel dispenser nozzle comprises a nozzle body for delivering liquid fuel from a fuel dispenser towards a vehicle fuel tank, and a nozzle spout associated with the nozzle body for delivering liquid fuel from the nozzle body into a vehicle fuel tank fill pipe inclined at approximately 30° down from horizontal. The nozzle spout has an inner wall surface defining a liquid flow passageway between the nozzle body and a spout tip. The wall surface has a first region extending from the spout tip and disposed with generally uniform radius about an axis, and a second region extending upstream from the first region to an aspirator ring and check valve assembly positioned in the liquid flow passageway relatively closer to, but spaced along, the liquid flow passageway from the nozzle body, the second region of the inner wall surface being flared in a upstream direction and disposed at a predetermined angle to the axis. With the spout tip engaged in the vehicle fill pipe and the axis disposed in general alignment with a vehicle fill pipe axis, the inner wall surface in the first region and the second region of the nozzle spout is disposed at effective angles below horizontal to encourage flow of liquid fuel toward the spout tip, whereby, when the spout tip is removed from the vehicle fill pipe after a predetermined interval following cessation of flow of fuel from the nozzle body into the liquid flow passageway of the nozzle spout, dripping of residual liquid fuel from the spout tip is limited to a predetermined average number of drops of liquid fuel per fueling event.

Preferred embodiments of this aspect may include one or more of the following additional features. Following cessation of flow of fuel from the nozzle body into the liquid flow passageway of the nozzle spout, the aspirator ring and check valve assembly seals an upstream portion of the liquid flow passageway, between the aspirator ring and check valve assembly and the nozzle body, to arrest leakage of residual fuel from the upstream portion into the first region and the second region of the liquid flow passageway downstream of the aspirator ring and check valve assembly for dripping from the spout tip. The predetermined interval of time is approximately 10 seconds. The predetermined average number of drops of liquid fuel dripped per fueling event is about 3 drops or less.

The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a side plan view of a fuel dispenser nozzle, while FIG. 2 is a side plan view, partially in section, of a nozzle spout assembly, both equipped with a first embodiment of a nozzle spout tip portion.

FIG. 3 is a side section view of the nozzle spout tip portion of FIG. 1.

FIG. 4 is a side section view of an alternate embodiment of the nozzle spout tip portion, while FIGS. 4A and 4B are front and side section views, respectively, of a dam insert configured for occupying a lower region of the annular volume defined by the dam in the nozzle spout tip portion of FIG. 4.

FIG. 5 is a side section view of a nozzle spout assembly equipped with another embodiment of nozzle spout tip portion.

FIG. 6 is side section view of the nozzle spout tip portion of FIG. 5.

FIG. 7 is a side section view of a nozzle spout assembly equipped with still another embodiment of nozzle spout tip portion.

FIG. 8 is side section view of the nozzle spout tip portion of FIG. 7.

FIG. 9 is a side section view of a vent tip assembly of FIG. 7.

FIGS. 10, 11 and 12 are side section, downstream end, and upstream end views, respectively, of an aspirator ring of FIG. 7.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, a fuel dispensing nozzle assembly 10, e.g., a 900 nozzle assembly as available from Healy Systems, Inc., of Hudson, N.H., consists of a nozzle body 12, e.g. formed of aluminum, joined to a flexible hose 14 for delivery of liquid fuel from, e.g., a fuel dispenser (not shown). Extending from the opposite end of the nozzle body 12 is a nozzle spout assembly 16 (shown in more detail in FIG. 2), which includes a spout tube 18 and terminates in a nozzle spout tip portion 20, for delivery of liquid fuel into a fill pipe of a motor vehicle fuel tank (not shown). The upper portion of the spout assembly 16, adjacent the nozzle body 12, is surrounded by a boot assembly 22. The flexible hose 24, nozzle body 12 and spout assembly 16 together define a conduit for the flow of gasoline from a fuel dispenser into the fill pipe of a motor vehicle fuel tank.

The nozzle assembly 10 reduces or, preferably, eliminates dripping of gasoline from the distal tip end 31 of the nozzle spout tip portion 20 as a fuel customer or service station attendant handles the nozzle assembly, e.g., prior to fueling, when inserting the nozzle spout tip portion 20 into the vehicle tank fill pipe, and after fueling, when returning the nozzle assembly 10 to the fuel dispenser holster. In accordance with CARB requirements, the process can be achieved with an average dripping loss of less than three (3) drops per fueling event.

Referring now to FIG. 3, in a first embodiment, the nozzle spout tip portion 20 has a spout tip body 32, with an inner wall surface 34 defining an axial flow conduit 36, and a generally cylindrical dam 38 extending coaxially with the flow conduit 36 at the upstream end 40 of the spout tip body 32. The dam 38 is formed by a tubular member 48 positioned within the spout tip body 32, with the downstream end 50 of the tubular member 48 engaged in a recess 52 defined by the inner wall surface 34 of the spout tip body 32. The tubular member 48 is preferably sized for pressure-fit with the recess 52 of the inner wall surface 34 and securely bonded thereto, e.g. with epoxy or other suitable adhesive, e.g. as available from Henkel Corporation, of Gulph Mills, Pa., under its trademark LOCTITE®. The upstream end 56 of the tubular member 48 is spaced from the inner wall surface 34 of the spout tip body 32 in a manner that defines an annular opening 58 into an annular volume 60 defined between the inner wall surface 34 of the spout tip body 32 where it tapers outwardly towards the upstream end 40, e.g. in a frusto-conical shape, and the outer surface 62 of the tubular member 48.

The annular volume 60 is positioned and configured for temporary storage of residual gasoline that may remain with the nozzle spout assembly 16, upstream of the dam 38, after cessation of flow of liquid fuel from the nozzle body 12, thereby restricting leakage of the residual liquid contained within the annular volume 60 in order to reduce or eliminate dripping of fuel from the spout tip end 31. Typically, with the nozzle spout tip assembly 16 inserted into the fill pipe of most typical motor vehicles, only a small volume of liquid fuel will remain in annular volume 60 behind the dam 38. The Society of Automotive Engineers (SAE) has established design requirements for motor vehicle fill pipes in ISO 13331, the complete disclosure of which is incorporated herein by reference. ISO 13331 provides that the centerline of a vehicle fill pipe (corresponding generally to the centerline or axis 64 of the nozzle spout tip portion 20 when inserted into the vehicle fill pipe) must be angled at least 30° down from horizontal. At this incline of 30°, the dam 38 will retain a volume of approximately twenty drops of gasoline. After allowing a suitable interval for drainage, e.g. about 10 seconds, the nozzle can be lifted slightly to disengage the nozzle spout assembly 16 from the fill pipe with the spout tip portion 20 remaining generally at the same angular attitude. If the spout tip portion 20 is then pointed downward, i.e. at approximately 90° down from horizontal, the dam 38 in the spout tip portion 20 has additional storage capacity of up to about forty drops of liquid gasoline from any upstream source. When the spout tip portion 20 is raised and the nozzle assembly 12 is returned to its normal holstered position on the fuel dispenser, liquid gasoline contained in the annular volume 60 behind the spout tip dam 38 drains back to the low point of the nozzle spout assembly 16, adjacent to the check valve 66 (FIG. 2).

Referring to FIGS. 4, 4A and 4B, in another embodiment of this aspect, a nozzle spout tip portion 20′ as a body 32′ and a liquid dam 38′ having an upstream flared portion 68 defining a wall surface 70 angled away from the centerline, 64′, of the spout tip portion 20′ at an angle, X, e.g., about 22°. A dam insert 72, formed, e.g., of aluminum, occupies a portion of the volume 60′ defined behind the dam 38′. For example, the insert 72 typically occupies an arcuate region, e.g. somewhat greater than about 180°, with its region of maximum thickness in the direction of flow lying in a lower region during dispensing of fuel, i.e. in the region over which the liquid fuel passes, below and in a vertical plane, V, of the axis 64′, aligned with the vent tip aperture 74 (FIG. 4). In each circumferential direction from the vertical plane, V, wing regions 76, 77 of dam insert 72 extend beyond a horizontal plane, H, of the axis 64′, i.e. the insert has an arcuate extent of more than about 180°, and the wing regions 76, 77 taper in the downstream direction at an angle, T, e.g. about 45°. The insert 72 serves to minimize the amount of liquid gasoline retained by the dam 38′ by substantially filling the volume that would otherwise be occupied by liquid when the spout tip is inclined downward 30° or more, while providing the remaining volume 60′ for retaining fuel remaining in the nozzle spout tube 18 upstream of the dam 38′ after the interval following cessation of liquid fuel flow. The insert 72 reduces the volume of gasoline collecting behind the dam 38′ by up to about twenty drops, thus reducing the volume of liquid gasoline available for evaporation between refueling episodes when the spout tip is raised and the nozzle is holstered.

Referring to FIGS. 5 and 6, according to another aspect, a spout tip assembly 116 includes a spout tip portion 120 having a spout tip body 132 defining an inner wall surface 134 with a conical or flared region 168 at the upstream end 140 of the spout tip body 132. The inner wall surface 134 defines a liquid fuel flow conduit or passageway 136 that is generally cylindrical over a downstream region 180 and conically tapering over an upstream region 182. The inner wall surface 183 in the tapered region 182 of the spout tip portion 120 has a taper angle, M, from the axis 164, e.g. about 22°.

In this example, the spout tip assembly 116 has the ability to fully drain the liquid flow conduit 136 when the spout tip center line 164 is inclined at an angle of at least about 30° down from the horizontal, e.g. as required when inserted into a motor vehicle fill pipe arrayed according to the SAE standard. When refueling a vehicle, the spout tip portion 120 is positioned generally in alignment with the centerline of the vehicle fill pipe. During fueling, this places the lowest portion of the surface 183 of the conical or flared region 182, i.e. that portion of the surface lying below and in a vertical plane, V, with the centerline or axis 164, lying at 22° to the axis 164, at a downward slope of about 8° to encourage drainage of liquid fuel from the conduit region 184 of the nozzle spout assembly 116 generally upstream of the conical tapered surface 183. Furthermore, the nozzle spout body 188 in the region 186 has a tapered surface 190 disposed at an angle, T, e.g. approximately 7° to the axis 192. As a result, with the nozzle spout tip portion 120 engaged in, and disposed generally in alignment with, a vehicle fuel tank fill pipe disposed generally at an angle of about 30° down from the horizontal, as required by SAE standards, the tapered surface 190 is disposed at an effective downward slope of about 1°, which further facilitates drainage of liquid fuel along the inner wall surface 134 of the nozzle spout assembly 116, towards the distal tip end 131. As mentioned, the inner wall surface 134 in the downstream region 180 of the nozzle tip spout 120 is disposed at 30° down from horizontal. Vehicle fill pipes disposed at angles in excess of 30° down from horizontal will directly increase the drainage slope achieved by the nozzle spout assembly 116.

Testing of the nozzle spout assembly of FIGS. 5 and 6 in accordance with CARB test procedures has shown complete drainage of liquid gasoline if sufficient time is allowed after cessation of fuel delivery. In particular, testing in accordance with CARB requirements has shown that a ten second delay for liquid drainage following cessation of fuel delivery will result in 3 drops or less spilled on average for vehicles meeting the SAE motor vehicle fill pipe design requirements.

Referring now to FIGS. 7 and 8, according to still another aspect, a nozzle spout assembly 216 consists of a spout tip portion 220 attached to a spout tube 218. The spout tip portion 220 consists of a spout tip body 232 having an inner wall surface 234 defining a flow conduit 236 with a tapered conical region 268 generally at the upstream end 240 of the spout tip body 232. The inner wall surface 283 in the tapered conical region 268 of the spout tip portion 220 has a taper angle, Y, from the axis 264, e.g. about 11.5°. The nozzle spout tip portion 220 is joined in smooth transition with the nozzle spout tube 218 (FIG. 7), which seats a relocated aspirator ring and check valve assembly 300. A vent tube 302, the function of which will be discussed more fully below, extends through a flow conduit 304 defined by the spout tube 218, from a vent elbow 306 of vent tip assembly 307 (FIG. 9), adjacent the distal tip end 231 of the spout tip portion 220, to attachment to a housing 308 at the proximal end of the nozzle spout assembly 216. In one example, the spout tube is bent at angle Z, e.g. about 22°. A check valve element 310 disposed within a chamber portion 312 at the intersection of the spout tube 218 with the nozzle spout tip portion 220, i.e. spaced from the nozzle body 12, is urged by compression spring 314, disposed within an axial bore of check valve element 310, into sealing engagement with a seat surface 316 defined by the aspirator ring 320 (FIGS. 10-12), with u-cup seal 322 disposed in sealing engagement between the check valve element 310 and a surface region 305 (FIG. 9) at the upstream end of the vent tip assembly 307, in a manner to prevent drainage of fuel from upstream of the aspirator ring and check valve assembly 300 upon cessation of fuel delivery flow. The fuel passage defined between the check valve element 310 and the surrounding seat surface 316 of the aspirator ring 320 is configured to cause liquid fuel flowing through this narrow passageway to create a Venturi effect for generating a vacuum drawn through vent conduit 326. The inner or upstream end of the vent conduit 326, defined by the vent tube 328, connects to a vent passageway 318 defined by the spout housing 308, which in turn connects to a vent passageway defined by the nozzle body, e.g. as fully described in commonly owned U.S. Pat. No. 5,327,944, the entire disclosure of which is incorporated herein by reference.

The configuration of this aspect results in complete gravity drainage of liquid fuel downstream of the sealing point between the check valve element 310 and aspirator ring 320. Drainage from nozzle spout assembly 216 downstream of the check valve element 310 can be typically relatively more rapid, e.g., as compared to the arrangements of FIGS. 5 and 6, since the wetted surfaces are comparably smaller and have steeper drain angles.

A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims. 

1. A fuel dispensing nozzle, comprising: a nozzle body, a nozzle spout having a nozzle spout tip extending distally from said nozzle body, said nozzle spout defining a conduit for flow of fuel from said nozzle spout tip into a vehicle fuel tank fill pipe, and a dam disposed within said nozzle in communication with said conduit and defining a reservoir region for restricting draining of liquid fuel towards said nozzle tip, with said nozzle spout tip engaged in the vehicle fuel tank fill pipe and said nozzle spout disposed at a first angular orientation below horizontal, said dam defines a first volume of said reservoir region for retaining fuel against draining past said dam to drip from said nozzle spout tip, and with said nozzle spout tip disengaged from the vehicle fuel tank fill pipe and said nozzle spout disposed at a second angular orientation below horizontal greater than said first angular orientation below horizontal, said dam defines a second volume greater than said first volume of said reservoir region for retaining fuel against draining past said dam to drip from said nozzle spout tip.
 2. The fuel dispensing nozzle of claim 1, wherein said dam is disposed within said nozzle spout.
 3. The fuel dispensing nozzle of claim 1, wherein said first angular orientation below horizontal is about 30° below horizontal.
 4. The fuel dispensing nozzle of claim 3, wherein said first volume of said reservoir region for retaining fuel is about 20 drops.
 5. The fuel dispensing nozzle of claim 1 or claim 3, wherein said second angular orientation below horizontal is up to about 90° below horizontal.
 6. The fuel dispensing nozzle of claim 5, wherein said second volume of said reservoir region for retaining fuel is up to about 40 drops.
 7. The fuel dispensing nozzle of claim 1, wherein said dam comprises a cylindrical wall member disposed coaxially within said nozzle spout.
 8. The fuel dispensing nozzle of claim 7, wherein said cylindrical wall member comprises a cylindrical tubular insert disposed in engagement with the wall of said conduit.
 9. The fuel dispensing nozzle of claim 1, wherein a segment of said annular volume is occupied, including in at least a lower region when dispensing fuel.
 10. The fuel dispensing nozzle of claim 1, wherein said annular volume is occupied over an arcuate segment, including at least a lower region when dispensing fuel.
 11. The fuel dispensing nozzle of claim 10, wherein said arcuate segment extends more than 180°, including at least through said lower region when dispensing fuel.
 12. The fuel dispensing nozzle of claim 9, claim 10 or claim 11, wherein said annular volume is occupied by an insert member.
 13. A fuel dispenser nozzle comprising: a nozzle body for delivering liquid fuel from a fuel dispenser towards a vehicle fuel tank, and a nozzle spout associated with said nozzle body for delivering liquid fuel from said nozzle body into a vehicle fuel tank fill pipe inclined at approximately 30° down from horizontal, said nozzle spout having an inner wall surface defining a liquid flow passageway from said nozzle body to a spout tip, said wall surface having a first region extending to said spout tip and being disposed with generally uniform radius about an axis, and a second region upstream from said first region and relatively closer to said nozzle body and being flared in a upstream direction, said second region of said inner wall surface being disposed at a predetermined angle to said axis, with said spout tip engaged in the vehicle fill pipe and said axis disposed in general alignment with a vehicle fill pipe axis, said inner wall surface in said first region and said second region being disposed at effective angles below horizontal to encourage flow of liquid fuel toward said spout tip, whereby, when said spout tip is removed from the vehicle fill pipe after a predetermined interval following cessation of flow of fuel from said nozzle body into said liquid flow passageway of said nozzle spout, dripping of residual liquid fuel from said spout tip is limited to a predetermined average number of drops of liquid fuel per fueling event.
 14. The fuel dispenser nozzle of claim 13, wherein the predetermined interval of time is approximately 10 seconds.
 15. The fuel dispenser nozzle of claim 13 or claim 14, wherein the predetermined average number of drops of liquid fuel dripped per fueling event is about 3 drops or less.
 16. A fuel dispenser nozzle comprising: a nozzle body for delivering liquid fuel from a fuel dispenser towards a vehicle fuel tank, and a nozzle spout associated with said nozzle body for delivering liquid fuel from said nozzle body into a vehicle fuel tank fill pipe inclined at approximately 30° down from horizontal, said nozzle spout having an inner wall surface defining a liquid flow passageway from said nozzle body to a spout tip, said wall surface having a first region extending to said spout tip and being disposed with generally uniform radius about an axis, a second region upstream from said first region and relatively closer to said nozzle body and being flared in a upstream direction, said second region of said inner wall surface being disposed at a first predetermined angle to said axis, and a third region upstream of said second region and relatively closer to the nozzle body and flared in an upstream direction, said third region of said inner wall surface being disposed at a second predetermined angle to said axis, with said spout tip engaged in the vehicle fill pipe and said axis disposed in general alignment with a vehicle fill pipe axis, said inner wall surface in said first region, said second region, and said third region being disposed at effective angles below horizontal to encourage flow of liquid fuel toward said spout tip, whereby, when said spout tip is removed from the vehicle fill pipe after a predetermined interval following cessation of flow of fuel from said nozzle body into said liquid flow passageway of said nozzle spout, dripping of residual liquid fuel from said spout tip is limited to a predetermined average number of drops of liquid fuel per fueling event.
 17. The fuel dispenser nozzle of claim 16, wherein the predetermined interval of time is approximately 10 seconds.
 18. The fuel dispenser nozzle of claim 16 or claim 17, wherein the predetermined average number of drops of liquid fuel dripped per fueling event is about 3 drops or less.
 19. The fuel dispenser nozzle of claim 16, wherein said first predetermined angle is about 22° to said axis.
 20. The fuel dispenser nozzle of claim 16 or claim 17, wherein said second predetermined angle is about 7°to said axis.
 21. A fuel dispenser nozzle comprising: a nozzle body for delivering liquid fuel from a fuel dispenser towards a vehicle fuel tank, and a nozzle spout associated with said nozzle body for delivering liquid fuel from said nozzle body into a vehicle fuel tank fill pipe inclined at approximately 30° down from horizontal, said nozzle spout having an inner wall surface defining a liquid flow passageway between said nozzle body and a spout tip, said wall surface having a first region extending from said spout tip and being disposed with generally uniform radius about an axis, and a second region extending upstream from said first region to an aspirator ring and check valve assembly positioned in said liquid flow passageway relatively closer to but spaced along said liquid flow passageway from said nozzle body, said second region of said inner wall surface being flared in a upstream direction and disposed at a predetermined angle to said axis, with said spout tip engaged in the vehicle fill pipe and said axis disposed in general alignment with a vehicle fill pipe axis, said inner wall surface in said first region and said second region of said nozzle spout being disposed at effective angles below horizontal to encourage flow of liquid fuel toward said spout tip, whereby, when said spout tip is removed from the vehicle fill pipe after a predetermined interval following cessation of flow of fuel from said nozzle body into said liquid flow passageway of said nozzle spout, dripping of residual liquid fuel from said spout tip is limited to a predetermined average number of drops of liquid fuel per fueling event.
 22. The liquid fuel dispenser nozzle of claim 21, wherein, following cessation of flow of fuel from said nozzle body into said liquid flow passageway of said nozzle spout, said aspirator ring and check valve assembly seals an upstream portion of said liquid flow passageway, between said aspirator ring and check valve assembly and said nozzle body, to arrest leakage of residual fuel from the upstream portion into said first region and said second region of said liquid flow passageway downstream of the aspirator ring and check valve assembly for dripping from said spout tip.
 23. The fuel dispenser nozzle of claim 21, wherein the predetermined interval of time is approximately 10 seconds.
 24. The fuel dispenser nozzle of claim 21 or claim 23, wherein the predetermined average number of drops of liquid fuel dripped per fueling event is about 3 drops or less. 